* lisp/cus-start.el: Explanatory comment.

diff --git a/lisp/cus-start.el b/lisp/cus-start.el
index 388a314c5c57cb920f8d603faaf297e7528cf777..750b6570158be85a852ad2e689402d9dba65ae0c 100644 (file)
--- a/lisp/cus-start.el
+++ b/lisp/cus-start.el
@@ -34,6 +34,19 @@
 
 ;;; Code:
 
+;; Elements of this list have the form:
+;; SYMBOL GROUP TYPE VERSION REST...
+;; SYMBOL is the name of the variable.
+;; GROUP is the custom group to which it belongs (may also be a list
+;; of groups)
+;; TYPE is the defcustom :type.
+;; VERSION is the defcustom :version (or nil).
+;; REST is a set of :KEYWORD VALUE pairs.  Accepted :KEYWORDs are:
+;; :standard - standard value for SYMBOL (else use current value)
+;; :set - custom-set property
+;; :risky - risky-local-variable property
+;; :safe - safe-local-variable property
+;; :tag - custom-tag property
 (let ((all '(;; alloc.c
             (gc-cons-threshold alloc integer)
             (garbage-collection-messages alloc boolean)